Major trends in health and healthcare make a significant investment in training public and population health informatics (PHI) researchers particularly compelling. These trends include (1) the increasing realization of the importance of social, environmental, and behavioral factors as determinants of human health; (2) the requirement to train experts who can support local, state, and federal health agencies with informatics research and development; and (3) the urgent need to help the healthcare system develop capacity in community and population health management, as well as data analytics, to help it transition to a model emphasizing prevention and wellness rather than intervention. Therefore we propose a multi-disciplinary training program in PHI. Through access to unparalleled population-level data, education in population health and informatics methods, and experiences working on a broad range of innovative PHI research projects, we will help trainees become independent scientists capable of designing, developing, implementing and evaluating advanced information systems in clinical and public health settings. Our program will incrementally grow from an initial set of 12 trainees (6 predoctoral, 6 postdoctoral) to 17 total trainees (9 predoctoral, 8 postdoctoral) in the fifth year. Predoctoral trainees will complete a doctoral degree in either Epidemiology or Health Policy & Management, with a concentration in PHI. Postdoctoral trainees will complete their MPH with a concentration in PHI. Furthermore, expert faculty will actively mentor trainees in hands-on research in areas such as health information exchange (HIE), detection of notifiable diseases from HIE data streams, rapid identification and notification of emerging health threats (syndromic surveillance), HIE- based computer-based decision support to improve primary care, and informatics methods to help improve chronic pain care and prevent prescription drug abuse. Research experiences will include both retrospective, observational studies involving health data from multiple health systems, as well as prospective experiences involving a local health system partner. Trainees will also complete a broad set of workshops and seminars that will equip them with knowledge and skills essential to BMI research, such as the responsible conduct of research, team science, and research ethics. Building upon a strong legacy of research and educational collaborations, we will successfully train a cadre of researchers capable of leading the design, development and evaluation of next generation PHI systems. Collectively our faculty and trainees will work on research that can be translated to public health agencies and health care delivery systems to transform care delivery as well as outcomes.